Seeking SR20 Advice!

[CleanSfourteen]

So I picked up this SR20DE shortblock a little while ago and I've had it sitting on the stand for a couple of weeks now. I think I would like to rebuild the bottom end with the DET parts and I was trying to stay away from getting new sleeves.

So I was wondering what you all thought, pictures don't lie.



A little carbon on the piston tops, but I was planning on getting new pistons.



IMO, this sleeve looks great, you can still see the marks from the honing process in the metal.



This is the sleeve that has me worried, I can't decide if that's corrosion or a wear mark..



Also here on the crankshaft, wear mark or corrosion???

I would appreciate a few other opinions, this is my first motor build and I would like to do it right.

[CleanSfourteen]

Don't you all fight to make the first post!!!!

Seriously, this is just a 'what do you think?' sorta thread, I don't have time to tear down this block at the moment, so I don't have the luxury of measuring. I'm going to be in a few places I know I can find cheap SR parts, so it would be nice to know what I need before I get there....

Any help at all would be nice, I see 33 views and no posts, don't be afraid lurkers!!! your opinion counts too!

[AZhitman]

Why not just get the bores machined? You're gonna buy new pistons, get oversized ones and be done with it.

Hard to tell anything from that last pic, you have to disassemble to get a good look.

You'll want to put in new bearings anyway, so start disassembling PER THE FSM.

Get a good micrometer, a FSM, and take your time. Shortcuts = BOOM.

[CleanSfourteen]

Why not just get the bores machined? You're gonna buy new pistons, get oversized ones and be done with it.

The thought has crossed my mind, but I wouldn't mind keeping stock bore. I was planning on using mostly OEM SR20DET parts. I get paranoid with aluminum blocks, and I'm still not sure if I should boost this motor or not...

I understand that the pics are hard to make anything out of, but this project will be on hold all summer while I build funds. And believe me, EVERYTHING is coming apart and I'm sure just about everything will be replaced. I'm trying to avoid that whole "boom" thing!

Thanks for the advice, I think I will most likely have the block machined. I was just wondering if new sleeves were needed.

[Slipstream]

Along with what AZHitman said, I would invest in a dial bore gauge to measure your cylinder, and main bores. Measure your rod and main journals. Basically measure everything that has a spec. You might find out that you have to run larger pistons, oversized bearings. It's not easy at all to just jump into doing a build.

[CleanSfourteen]

As I said above, everything will be coming apart and everything that has a spec will be measured and checked against my trusty FSM.

The sole reason of this post was to determine if those little marks are corrosion, or wear marks. They appear to be corroision to me, but as I said I would like more opinions.

and I don't see how I am "just jumping into doing a build"... As I posted above, I'm not even taking anything apart yet. . . all in good time, all I have is a short block for now.

Thanks for the advice tho!

[Slipstream]

It looks just like normal corrosion. The rings don't hit all the way to the top of the cylinder wall, and if it's been sitting there for awhile it will build up. You can spray it down with WD40 and repeatedly wipe it and then spray a little on it after your down to keep it from rusting again. Not trying to be rude about the jumping into a build part, just saying it's a lot of work and frustrating. I'm in the middle of a build myself right now. 2 separate engines, and still replacing a ton of parts.

[CleanSfourteen]

Excellent, I'm glad to see that someone agrees with me. I was however talking about lower down in the cylinder wall, there seems to be a small ring of what i guess is rust, but it doesn't form a complete ring around the cylinder. That's why I was getting nervous, thinking that this could be caused by something like piston out of round.



I understand the frustration with building a motor, this is my side project while I keep my KA24DE kouki at DD status. In about two months it will be at 100K and the timing set is being replaced, along with anything else that seems worn while I have the motor on the hoist. Needless to say, I don't have all the money in the world to throw at my SR. But I'm not in a rush, I don't even have a vehicle to put the motor in yet, I'm thinking 70's Datsun pickup!

[Slipstream]

It was probably from one of the rings staying there without being moved in awhile. When I had mine on the stand before I started working on it, I'd turn it every couple of days with a squirt to keep it lubed.

I'm deciding if I'm even gonna install mine, or just sell it and build my KA.